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[英]Hibernate:org.hibernate.NonUniqueObjectException:
[英]org.hibernate.NonUniqueObjectException when saving a list of child objects
創建父對象時,我需要保存幾個子對象。 理想情況下,我想將它們保存在一個事務中,但是,我不斷收到org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session
。
在此示例中,SubDiscipline具有許多SubdisciplinePlayers。
我覺得映射有問題
public class Subdiscipline {
private int id;
private int disciplineId;
private String name;
private List<SubdisciplinePlayer> subdisciplinePlayers;
public Subdiscipline() {
}
//standard constructors, getter & setters...
}
public class SubdisciplinePlayer implements Serializable {
private int idPlayers;
private int disciplineId;
private int subDisciplineId;
private int players;
private int minPlayers;
private int maxPlayers;
private Subdiscipline subdiscipline;
public SubdisciplinePlayer() {
}
//standard constructors, getter & setters...
}
public class Main {
@SuppressWarnings("unchecked")
public static void main(String[] args) {
SessionFactory sf = HibernateUtil.getSessionFactory();
Session session = sf.openSession();
session.beginTransaction();
Subdiscipline sd = new Subdiscipline("soccer_" + (new Date()).getTime(), new Date(), new Date(), new Status(1) );
sd.setDisciplineId(4);
session.save(sd);
SubdisciplinePlayer sdp = new SubdisciplinePlayer();
sdp.setDisciplineId(sd.getDisciplineId());
sdp.setSubDisciplineId(sd.getId());
sdp.setSubdiscipline(sd);
sdp.setIdPlayers(555);
SubdisciplinePlayer sdp2 = new SubdisciplinePlayer();
sdp2.setDisciplineId(sd.getDisciplineId());
sdp2.setSubDisciplineId(sd.getId());
sdp2.setSubdiscipline(sd);
sdp2.setIdPlayers(457);
sd.setSubdisciplinePlayers(new ArrayList<SubdisciplinePlayer>());
sd.getSubdisciplinePlayers().add(sdp);
sd.getSubdisciplinePlayers().add(sdp2);
session.save(sd);
session.getTransaction().commit();
session.close();
}
}
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="net.viralpatel.hibernate.Subdiscipline" table="sub_discipline">
<id name="id" column="sub_dis_id" unsaved-value="0">
<generator class="increment"/>
</id>
<property name="disciplineId" column="dis_id" type="int"/>
<property name="name" column="sub_discipline" type="string"/>
<bag name="subdisciplinePlayers" table="sdis_players" inverse="true" cascade="all">
<key column="sub_dis_id" />
<one-to-many class="net.viralpatel.hibernate.SubdisciplinePlayer" />
</bag>
</class>
</hibernate-mapping>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="net.viralpatel.hibernate.SubdisciplinePlayer" table="sdis_players">
<composite-id>
<key-property name="disciplineId" column="dis_id" type="int"/>
<key-property name="subDisciplineId" column="sub_dis_id" type="int" />
</composite-id>
<property name="idPlayers" column="id_players" type="int"/>
<property name="players" column="players" type="int"/>
<property name="minPlayers" column="min_players" type="int"/>
<property name="maxPlayers" column="max_players" type="int"/>
<many-to-one name="subdiscipline" class="net.viralpatel.hibernate.Subdiscipline" cascade="none" insert="false" update="false">
<column name="sub_dis_id"/>
</many-to-one>
</class>
</hibernate-mapping>
Exception in thread "main" org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [net.viralpatel.hibernate.SubdisciplinePlayer#net.viralpatel.hibernate.SubdisciplinePlayer@1cd7e9c3]
您已為實體SubdisciplinePlayer
聲明了帶有disciplineId
subDisciplineId
和subDisciplineId
字段的組合鍵。
現在,在您的程序中,您將創建兩個具有相同組合ID的SubdisciplinePlayer
實例。
SubdisciplinePlayer sdp = new SubdisciplinePlayer();
sdp.setDisciplineId(sd.getDisciplineId());
sdp.setSubDisciplineId(sd.getId());
SubdisciplinePlayer sdp2 = new SubdisciplinePlayer();
sdp2.setDisciplineId(sd.getDisciplineId());
sdp2.setSubDisciplineId(sd.getId());
因此,當您調用Session.save(sd)
,hibernate觀察到您正在嘗試保存2個SubdisciplinePlayer
實例, SubdisciplinePlayer
異常拋出為:
org.hibernate.NonUniqueObjectException: a different objectwith the same identifier
value was already associated with the session:
[net.viralpatel.hibernate.SubdisciplinePlayer#
net.viralpatel.hibernate.SubdisciplinePlayer@1cd7e9c3]
要解決此問題,只需確保SubdisciplinePlayer
的復合ID應該具有不同的值,因為主鍵應該是唯一的。
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